Vitamins

Question 1

Name and class of Vitamin A

Answer 1

Retinol; fat soluble

Question 2

Name and class of Vitamin D

Answer 2

Calciferols; fat soluble

Question 3

Name and class of Vitamin E

Answer 3

Tocopherols; fat soluble

Question 4

Name and class of Vitamin K

Answer 4

Quinones; fat soluble

Question 5

Name and class of Vitamin C

Answer 5

Ascorbic acid; water soluble

Question 6

Name and class of Vitamin B1

Answer 6

Thiamin; water soluble

Question 7

Name and class of Vitamin B2

Answer 7

Riboflavin; water soluble

Question 8

Name and class of Vitamin B3

Answer 8

Nicotinic acid / niacin; water soluble

Question 9

Name and class of Vitamin B5

Answer 9

Pantothenic acid; water soluble

Question 10

Name and class of Vitamin B6

Answer 10

Pyridoxine; water soluble

Question 11

Name and class of Vitamin B7

Answer 11

Biotin; water soluble

Question 12

Name and class of Vitamin B9

Answer 12

Folic acid; water soluble

Question 13

Name and class of Vitamin B12

Answer 13

Cyanocobalamin; water soluble

Question 14

Metabolic function of retinol

Answer 14

Formation & integrity of epithelia & mucous membranes

Retinal function
- Combines with opsin to form rhodopsin needed for ‘night vision’

Bone growth

Immune function

Question 15

Sources of retinol

Answer 15

Liver (cod liver oil)
- Accumulates and stored in the liver of animals
Egg yolk
Milk fat

Question 16

Problems with deficiency of retinol in cattle

Answer 16

Mild deficiency - rough scaly skin

Prolonged deficiency - ‘Night blindness’, lachrymation, corneal opacity. Infertility, abortion, retained placenta, still-birth

Deficiency rare in adults as carotenoids acquired at pasture replenish hepatic stores of Vitamin A -> able to provide adequate retinol cover over winter periods (except if history of liver &/or intestinal disease)

Intensively reared indoor beef cattle on cereal diets (barley beef) are prone

Question 17

Problems with deficiency of retinol in poultry

Answer 17

Symptoms appear quickly (2-3 weeks)

Pale comb & wattles, loss of condition, retarded growth, ruffled plumage, general unthriftiness

Susceptible to infectious diseases

High mortality rate

Poultry feeds require Vitamin A supplement

Question 18

Problems with deficiency of retinol in dogs and cats

Answer 18

Deficiencies can occur e.g. if fed all-meat diets without liver

Dogs - scurfy, scaly skin (first sign); ‘night blindness’; abnormal skeletal growth

Cats - foetal defects are apparent & complete infertility can result

Question 19

Problems with excess of retinol in dogs and cats

Answer 19

Abnormal bone deposition
Lameness
Vertebral spondylosis
Gingivitis
Weight loss
Poor coat
(Caused by excess fish liver oil and/or liver intakes)

Question 20

Problems with excess of retinol in pigs

Answer 20

Excessive intakes of retinol in pregnant sows may cause cardiac abnormalities in piglets

Question 21

Metabolic function of the calciferols

Answer 21

Promotes Ca2+ absorption from digesta in the gut lumen

When blood Ca2+ concentrations decrease, it enhances intestinal absorption of Ca

Stimulates phosphorous uptake from gut & reabsorption of both Ca2+ and P from bone and kidney

i.e. it helps regulate the amount of calcium and phosphorus in the body
Metabolism of Vit D, Calcium and Phosphorus are related

Question 22

Sources of the calciferols

Answer 22

Sunlight on skin
Fish (oily)
Egg yolk
Hay (sun-dried roughages)
Colostrum (6-10x milk)

Question 23

Problems with deficiency of the calciferols

Answer 23

RICKETS – soft weak deformed bones in young growing animals

Osteomalacia in adults (weak bones)

Poor egg sell quality and weak bones in poultry

Question 24

Sources of α-Tocopherol

Answer 24

Little body reserve so dietary intake is important
Green fodder (grass, green vegetables)
Cereals (↑barley, ↓maize), but decreases rapidly during storage

Question 25

Metabolic functions of α-Tocopherol

Answer 25

Biological antioxidant Acts in combination with the selenium (Se) containing enzyme, glutathione peroxidase, to protect cells from oxidative damage caused by free radicals (reactive compounds produced during cell metabolism which are capable of damaging cell membranes) Important for normal reproductive function, muscular function & capillary integrity

Question 26

Problems with deficiency of α-Tocopherol

Answer 26

Nutritional myopathy -White muscle disease (calves) -Stiff lamb diseases Cardiac disease -Mulberry heart disease (pigs, calves) Brain damage -Crazy chick disease Lameness & muscle stiffness -Tying-up (horses)

Question 27

Sources of quinones

Answer 27

Green, leafy materials Egg yolk, liver & fish Gut bacteria synthesise

Question 28

Metabolic functions of quinones

Answer 28

Essential for the normal clotting of blood Bone & kidney function

Question 29

Problems with deficiency of quinones

Answer 29

Unlikely to occur in cattle, horses or pigs Usually no dietary requirement for ruminants as microbial population of the rumen can synthesise Chicks: anaemia & delayed clotting of blood

Question 30

Sources of B complex vitamins

Answer 30

Liver Yeasts Green foods Cereals (+/-) Milk (+/-)

Question 31

Metabolic functions of B complex vitamins

Answer 31

Pathways of cellular respiration & energy transfer Co-enzymes

Question 32

Metabolic functions of thiamine

Answer 32

Initiation & propagation of nerve impulses

Question 33

Problems with deficiency of thiamine

Answer 33

progressive dysfunction of the nervous system -paralysis -blindness -muscular dysfunction -Loss of appetite -emaciation

Question 34

Metabolic functions of riboflavin

Answer 34

Vital for oxidative phosphorylation and H+ transport

Question 35

Problems with deficiency of riboflavin

Answer 35

Pigs: Poor appetite & growth; skin eruptions; vomiting; eye abnormalities; infertility & abortion Chicks: ‘Curled toe paralysis’ (neural degeneration, walk on hocks) Ruminants: Inappetance, diarrhoea, mouth lesions

Question 36

Problems with deficiency of the pyridoxines

Answer 36

Rare due to wide distribution in many foods (inclu. milk) & gut microbial synthesis Chicks: neural degeneration & jerky gait

Question 37

Metabolic functions of cyanocobalamin

Answer 37

Important coenzyme in cellular respiratory pathways

Question 38

Problems with deficiency of cyanocobalamin

Answer 38

Mostly young animals  poor growth

Question 39

Sources of ascorbic acid

Answer 39

Citrus fruits Green, leafy vegetables Synthetic

Question 40

Metabolic functions of ascorbic acid

Answer 40

Normal collagen formation Metabolic oxidation & reduction pathways Iron transport Antioxidant Only essential in the diet of primates (incl. man), guinea pigs, fruit bats Other species synthesise it from glucose

Question 41

Problems with deficiency of ascorbic acid

Answer 41

Scurvy -muscle and joint pain –> reluctance / difficulty moving -lethargy -the appearance of red dots on the skin -bleeding and swelling of the gums -diarrhoea -weight loss -rough hair coat -reduced immune function